Variable Focusing Fluid Lens with Cam Belt Actuation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing variable focusing power optical devices, particularly non-round lenses, face challenges in achieving optimal optical performance due to the need for precise control of membrane shape and distribution of control points, which is difficult to achieve especially in regions like the nose where improved optics are required.
Innovation Solution
A variable focusing power fluid-filled lens or mirror assembly with a distensible membrane held under tension by a supporting structure featuring multiple discrete control points and an actuation mechanism, including cam members and a cam belt system, allows for bidirectional rotation and differential displacement of the membrane edge to control its shape and curvature.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a distensible membrane is used to create variable focusing power, then the lens can achieve adjustable optical power, but the membrane shape control and optical quality become difficult to achieve, especially in non-round lenses
Solution Approach 1:
The membrane supporting structure is divided into multiple discrete control points (at least three, preferably four or more) distributed around the periphery of the membrane. Each control point can be independently actuated to apply localized forces, enabling precise control of the membrane's three-dimensional shape. This segmentation allows the membrane to be shaped into spherical or spherocylindrical surfaces required for high-quality optics.
Solution Approach 2:
Different regions of the membrane periphery are assigned different functions through the distribution of control points. Static control points (hinge points) maintain fixed positions to provide stability, while active control points are moved by actuators to actively shape the membrane. This local differentiation enables precise control of membrane curvature and shape in specific regions, achieving the required optical surfaces.
2Manufacturing precision
If multiple control points are used around the membrane periphery, then the optical quality can be improved, but the device complexity increases
Solution Approach 1:
A single actuator mechanism is designed to perform multiple functions: it can actuate multiple active control points around the membrane periphery, and the same mechanism can accommodate different lens shapes (spherical, spherocylindrical, and other non-round shapes). The cam mechanism with adjustable cam profiles provides universal control for various optical requirements without requiring separate actuators for each control point.
Solution Approach 2:
Multiple control functions are merged into a single integrated actuation system. The cam mechanism combines the actuation of all active control points into one mechanical system that can be driven by a single motor or actuator. This merging reduces the overall device complexity while maintaining the capability to control multiple membrane regions independently.
3Stability of the object's composition
If the membrane is held under tension by a rigid supporting structure, then the membrane stability is improved, but the ability to actively control membrane shape at multiple points is reduced
Solution Approach 1:
The supporting structure is designed with a combination of static and dynamic elements. The overall structure maintains the membrane under tension for stability, while specific control points are made movable through cam mechanisms that can dynamically adjust the membrane position at those points. This dynamic capability allows active shape control while maintaining overall membrane stability through the tensioned configuration.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This design enhances optical performance by enabling active control at multiple points around the eye-shape, improving optics and allowing for a greater range of eye-shapes to be accommodated, with the ability to minimize lens thickness and achieve spherical or spherocylindrical optical surfaces of high quality.
Implementation Method 1
The pressure of the fluid within the envelope may be adjustable to cause the distensible membrane to distend outwardly or to retract inwardly
Implementation Method 2
a first wall that is formed of a distensible elastic membrane
Implementation Method 3
an actuation mechanism for displacing the edge of the membrane on the z-axis relative to the second wall at each of the actuation points
Data Source
AI summary
A variable focusing power fluid-filled lens or minor assembly (100a) comprising a fluid-filled envelope and a supporting structure (18) therefor; the fluid-filled envelope being constituted by a first wall that is formed of a distensible elastic membrane (15) having an exterior optical surface (151) of variable focusing power, a second wall (183) that is spaced from the first wall on a z-axis which is generally perpendicular to the membrane, and a collapsible peripheral side wall (17) that extends between the first and second walls (15, 183), and being filled with a substantially incompressible fluid (16); a membrane holding structure (14) that is attached to a peripheral edge of membrane for holding the membrane under tension, the membrane holding structure defining a plurality of discrete control points spaced around the peripheral edge of membrane where the position of the peripheral edge of the membrane relative to the second wall on the z-axis is controlled and permitting bending of the peripheral edge of the membrane between the control points in a plane defined by the z-axis and a tangent to the peripheral edge of the membrane; the plurality of control points including a plurality of dynamic actuation points; and an actuation mechanism for displacing the edge of the membrane on the z-axis relative to the second wall at each of the actuation points to control the shape of the membrane; wherein the actuation mechanism comprises a plurality of first cam members (5, 6, 7, 8) that are connected to the membrane holding structure and associated with respective actuation points, a cam belt disposed circumjacent the membrane which comprises a plurality of spaced second cam members (2, 101), each second cam member being engaged with a corresponding one of the first cam members for controlling the position of the edge of the membrane on the z-axis at the respective actuation point, a cam belt support (19) that supports the cam belt for bidirectional rotation around the z-axis relative to the membrane and a coupling (102) for drivably connecting the cam belt to a selectively operable driver (103).